Herbicidal composition

ABSTRACT

A herbicidal composition in the form of a two-phase aqueous emulsion which comprises,
         a) as organic phase, a solution of a herbicidally effective amount of the compound 2-(4-(3-chloro-5-fluoro-2-pyridyloxy)-phenoxy-propionic acid propargyl ester in a hydrophobic solvent and a substantially water-insoluble and hydrolysis-stable oil phase stabiliser and,   b) as aqueous phase, a solution of at least one surface-active compound and/or dispersing agent and a pH buffer in water.

The present invention relates to a herbicidal composition in the form ofan aqueous emulsion which comprises, as herbicidally effective compound,2-(4-(3-chloro-5-fluoro-2-pyridyloxy)-phenoxy-propionic acid propargylester, and to the use of that composition in controlling weeds in cropsof useful plants.

2-(4-(3-Chloro-5-fluoro-2-pyridyloxy)-phenoxy-propionic acid propargylester has herbicidal activity, especially in crops of cereals, rice andsoybeans; it is known by the name clodinafop-propargyl and is described,for example, in U.S. Pat. No. 4,713,109.

Clodinafop-propargyl is preferably used together with the safener2-(5-chloroquinolin-8-yloxy)-1-methylhexyl ester, which is known by thename cloquintocet-mexyl and is described, for example, in U.S. Pat. No.4,881,966. Both compounds are commercially available in the form of anemulsifiable concentrate (EC).

Aqueous emulsions for the formulation of pesticides are known per se andare described, for example, in U.S. Pat. No. 5,674,514. The problemsolved in U.S. Pat. No. 5,674,514 was to provide an aqueous emulsion forthe purpose of improving the storage stability of certain pesticides.U.S. Pat. No. 5,674,514 contains no reference whatsoever to changes inthe biological activity of pesticides formulated in that manner.

It has now been found, surprisingly, that the herbicidal activity ofclodinafop-propargyl can be considerably increased when that compound isapplied in the form of a particular aqueous emulsion.

The present invention accordingly relates to a herbicidal composition inthe form of a two-phase aqueous emulsion which comprises

-   a), as organic phase, a solution of a herbicidally effective amount    of the compound    2-(4-(3-chloro-5-fluoro-2-pyridyloxy)-phenoxy-propionic acid    propargyl ester in a hydrophobic solvent and a substantially    water-insoluble and hydrolysis-stable oil phase stabiliser and-   b), as aqueous phase, a solution of at least one surface-active    compound and/or dispersing agent and a pH buffer in water.

Preferred compositions according to the invention additionally comprisean amount, effective for antagonism of the herbicide, of2-(5-chloroquinolin-8-yloxy)-1-methylhexyl ester, its free acid or asalt thereof of formula

wherein M is a mono-, bi- or tri-valent metal, ammonium, N(R)₄ orHN(R)₃, wherein the substituents R are identical to or different fromone another and are C₁-C₁₆alkyl or C₁-C₁₆-hydroxyalkyl, or M is S(R₁)₃or P(R₁)₄, wherein the substituents R₁ are identical to or differentfrom one another and are C₁-C₂₀alkyl, C₂-C₂₀alkenyl, C₂-C₂₀alkynyl, arylsubstituted by C₁-C₂₀alkyl, C₂-C₂₀alkenyl or by C₂-C₂₀alkynyl orheteroaryl substituted by C₁-C₂₀alkyl, C₂-C₂₀-alkenyl or byC₂-C₂₀alkynyl, or 2 substituents R₁ together with the sulfur orphosphorus atom to which they are bonded form a 5- or 6-membered ring.

The metal atoms M that may be present in formula I are preferably thoseof alkali and alkaline earth metals, especially sodium, potassium,calcium, magnesium and also, especially, aluminium and iron as preferredrepresentatives of trivalent metals. Among the alkyl and hydroxyalkylsubstituents R, preference is given to those having from 12 to 16 carbonatoms and also to those having from 1 to 4 carbon atoms. The groupsN(R)₄ and HN(R)₃ especially contain one long-chain and 2 or 3short-chain alkyl group(s), for example hexadecyl-triethylammonium,tetradecyl-triethylammonium, dodecyltriethylammonium anddodecyl-ethyl-dimethylammonium, and also tetradodecylammonium. Preferredalkyl groups R₁ contain from 1 to 12, especially from 1 to 6, carbonatoms. The alkyl groups R and R₁ may be further substituted, for exampleby halogen, alkoxy or by haloalkoxy, in both cases preferably containingfrom 1 to 4 carbon atoms. Preferred alkenyl and alkynyl groups R₁contain from 2 to 12 carbon atoms. They may contain more than oneunsaturated bond and may be substituted by halogen, alkoxy or byhaloalkoxy, in both cases preferably containing from 1 to 4 carbonatoms. Suitable examples of aryl groups R₁ include phenyl, naphthyl,tetrahydronaphthyl, indanyl and indenyl, phenyl being preferred. Thosegroups may be substituted by the afore-mentioned alkyl, alkenyl andalkynyl groups. As heteroaryl groups R₁ there may be mentionedpreferably 5- and 6-membered rings containing especially nitrogen and/oroxygen atoms, for example pyridyl, pyrimidinyl, triazinyl, thienyl,thiazolyl, pyrazolyl, imidazolyl, piperidyl, dioxolanyl, morpholinyl andtetrahydrofuryl. Those heterocycles may also be further substituted bythe afore-mentioned alkyl, alkenyl and alkynyl groups. In each case, 2substituents R₁ together with the sulfur or phosphorus atom to whichthey are bonded may form a ring, in which case preference is given to 5-or 6-membered rings that are saturated. Sulfonium and phosphoniumcations suitable for use according to the invention are described, forexample, in WO 00/44227.

Preferred salts of 2-(5-chloroquinolin-8-yloxy)-1-methylhexyl estercomprise a compound of formula I wherein M is sodium, potassium ortri(hydroxyethylene)ammonium.

In a further group of preferred salts of2-(5-chloroquinolin-8-yloxy)-1-methylhexyl ester, M in formula I iscalcium, magnesium, aluminium, iron, trimethylsulfonium,triphenylsulfonium, tetraphenylphosphonium, triphenyl-methylphosphonium,triphenyl-benzylphosphonium, C₁₂-C₁₆alkyl-trimethylammonium,C₁₂-C₁₆alkyl-triethylammonium, tetradodecylammonium ordodecyl-ethyl-dimethylammonium.

The salts of formula I can be prepared by conventional methods, forexample by reacting 2-(5-chloroquinolin-8-yloxy)-1-methylhexyl esterwith an equimolar amount of a metal hydroxide in alcoholic solution atroom temperature.

The salts set out in the following Table can be prepared in that manner:

TABLE 1 Compounds of formula I: Compound no. M M.p. (° C.) 1.01 Na >2501.02 K >265 1.03 Ca 1.04 Mg 1.05 NH₄ 227-228 1.06 NH(CH₂CH₂OH)₃ 132-1521.07 N(C₁₂H₂₅)₄ 1.08 N(C₁₂H₂₅)(C₂H₅)(CH₃)₂ 1.09 N(C₁₂H₂₅)(CH₃)₃ 1.10N(C₁₂H₂₅)(C₂H₅)₃ 1.11 Al 1.12 Fe 1.13 H 232-233 1.14 S(CH₃)₃ 1.15S(C₆H₅)₃ 1.16 P(C₆H₅)₄ 1.17 P(C₆H₅)₃CH₃ 1.18 P(C₆H₅)₃CH₂C₆H₅

The compositions according to the invention may comprise one or moreherbicides in addition to clodinafop-propargyl. Such herbicides arepreferably selected from the groups of the sulfonylureas, sulfonamides,imidazolinones, carbazones, aryloxyphenoxypropionates,cyclohexanediones, arylcarboxylic acids and aryloxycarboxylic acids.Depending on their solubility, those herbicides may be dissolved eitherin the continuous aqueous phase or in the discontinuous oil phase or maybe suspended in either of the two phases.

As herbicides that are especially suitable for use in the compositionaccording to the invention mention may be made of, especially,sulfonylureas, preferably triasulfuron, tribenuron, metsulfuron,thifensulfuron, flupyrsulfuron, iodosulfuron, rimsulfuron, nicosulfuron,cinosulfuron, bensulfuron, trifloxysulfuron and analogues, and alsosulfonamides, preferably flumetsulam, metosulam, chloransulam,floransulam and analogues, and imidazolinones, preferably imazethabenz,imazethapyr, imazaquin, imazamox and analogues, and also carbazones,preferably flucarbazone, propoxycarbazine, amicarbazone and analogues,and also aryloxyphenoxypropionates, preferably fenoxaprop, diclofop,propaquizafop, quizalofop, fluazifop, cyhalofop, haloxyfop andanalogues, and also cyclohexanediones, preferably sethoxydim, clethodim,tralkoxydim and analogues, and arylcarboxylic acids, preferably dicambaand clopyralid, and also aryloxycarboxylic acids, preferably 2,4-D,mecoprop, fluroxypyr and analogues.

It has also been found, surprisingly, that clodinafop-propargyl andcloquintocet-mexyl are chemically especially stable in the aqueousemulsions according to the invention when the aqueous phase comprises apH buffer system. Suitable pH buffer systems in the context of thepresent invention are those mixtures of acids and salts that are capableof stabilising a pH of from 4 to 6, especially acetic acid/sodiumacetate, phosphoric acid/sodium phosphate or citric acid/citrate,preferably phosphoric acid/sodium phosphate or citric acid/citrate. Theaqueous phase of the compositions according to the invention arepreferably adjusted to a pH of 4 with phosphoric acid/sodium phosphateor citric acid/citrate.

The pH buffer is used in an amount of from 0.1 to 1 mol, preferably from0.2 to 0.7 mol, especially 0.5 mol, based on the aqueous phase.

In the context of the present invention, any solvent that issubstantially insoluble in water is suitable as the hydrophobic solvent,for example aromatic solvents selected from the classes of the toluenes,xylenes, alkylbenzenes and alkylnaphthalenes, and also saturated andunsaturated hydrocarbons, aryl-alkyl ketones, esters, fatty acid methylesters, rapeseed oil C₁-C₆alkyl esters, especially rapeseed oil methylester and rapeseed oil ethyl ester, esters of acetic acid or benzoicacid, amides of alkanecarboxylic acids, linear or cyclic acetates,alkylpyrrolidones, alkylcaprolactones and also alkyl carbonates ormixtures of those solvents. The solvent is preferably used in an amountof from 10 to 60% by weight, based on the complete formulation of theaqueous emulsion.

It has been found, moreover, that the chemical stability of thecompositions according to the invention can be further increased when ahydrophobic solvent preferably of especially high polarity is used inthe organic phase. In the context of the present invention, solvents ofhigh polarity are to be understood as solvents having a dipole moment ofat least 4×10⁻³⁰ Cm (coulomb×m). The hydrophobic solvents used in thecomposition according to the invention preferably have a dipole momentof at least 5×10⁻³⁰ Cm.

Especially preferred solvents are Exxate 700 (mixture of aliphaticacetic acid C₆-C₈ esters, Esso Switzerland), benzyl acetate, isobornylacetate, benzoic acid methyl ester or Solvesso 200(high-aromatic-content hydrocarbon mixture, manufacturer: ExxonChemicals).

Oil phase stabilisers that are especially suitable for the compositionaccording to the invention include the following polymers, copolymersand oligomers or mixtures thereof, selected from the classes of thepolystyrenes, water-insoluble poly(n-alkylene) glycols wherein n>2,polypropylene glycols, polyvinyl acetates and polyvinylacetate-co-polyethylenes.

Preferred oil phase stabilisers are:

-   1) Polymers of monoolefins and diolefins, for example polypropylene,    polyisobutylene, polybut-1-ene, polymethylpent-1-ene, polyisoprene    or polybutadiene and also polymers of cyclo-olefins, for example of    cyclopentene or norbornene, polyethylene (which may optionally be    cross-linked), for example high density polyethylene (HDPE), low    density polyethylene (LDPE) and linear low density polyethylene    (LLDPE).-   2) Mixtures of the polymers mentioned under 1), for example mixtures    of polypropylene with polyisobutylene, polypropylene with    polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of    different types of polyethylene (for example LDPE/HDPE).-   3) Copolymers of monoolefins and diolefins with one another or with    other vinyl monomers, for example ethylene/propylene copolymers,    linear low density polyethylene (LLDPE) and mixtures thereof with    low density polyethylene (LDPE), propylene/but-1-ene copolymers,    ethylene/hexene copolymers, ethylene/methylpentene copolymers,    ethylene/heptene copolymers, ethylene/octene copolymers,    propylene/butadiene copolymers, isobutylene/isoprene copolymers,    ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate    copolymers, ethylene/vinyl acetate or ethylene/acrylic acid    copolymers and salts thereof (ionomers), and also terpolymers of    ethylene with propylene and a diene, such as hexadiene,    dicyclopentadiene or ethylidenenorbornene; and also mixtures of such    copolymers with one another and with polymers mentioned under 1),    for example polypropylene/ethylene-propylene copolymers, LDPE/EVA,    LDPE/EAA, LLDPE/EVA and LLDPE/EAA.-   3a) Hydrocarbon resins (for example C₅-C₉) including hydrogenated    modifications thereof.-   4) Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).-   5) Copolymers of styrene or α-methylstyrene with dienes or acrylic    derivatives, for example styrene/butadiene, styrene/acrylonitrile,    styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate,    styrene/maleic acid anhydride, styrene/acrylonitrile/methyl    acrylate; mixtures consisting of styrene copolymers and another    polymer, for example a polyacrylate, a diene polymer or an    ethylene/propylene/diene terpolymer; and block copolymers of    styrene, for example styrene/butadiene/styrene,    styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or    styrene/ethylene/propylene/styrene.-   6) Graft copolymers of styrene or α-methylstyrene, for example    styrene on polybutadiene, styrene on polybutadiene/styrene or    polybutadiene/acrylonitrile; styrene and acrylonitrile (or    methacrylonitrile) on polybutadiene; styrene and maleic acid    anhydride or maleinimide on polybutadiene; styrene, acrylonitrile    and maleic acid anhydride or maleinimide on polybutadiene; styrene,    acrylonitrile and methyl methacrylate on polybutadiene, styrene and    alkyl acrylate or methacrylate on polybutadiene, styrene and    acrylonitrile on ethylene/propylene/diene terpolymer, styrene and    acrylonitrile on polyalkyl acrylates or polyalkyl methacrylates,    styrene and acrylonitrile on acrylate/butadiene copolymers, and    mixtures thereof with the copolymers mentioned under 5), for example    copolymer mixtures known under the designations ABS, MBS, ASA or    AES.-   7) Halogenated polymers, for example polychloroprene, chlorinated    rubbers, chlorinated or sulfonated polyethylenes, copolymers of    ethylene and chlorinated ethylene, epichlorohydrin homo- and    co-polymers, preferably polymers of halogenated vinyl compounds, for    example polyvinyl chloride, polyvinylidene chloride, polyvinyl    fluoride, polyvinylidene fluoride and copolymers thereof, for    example vinyl chloride/vinylidene chloride, vinyl chloride/vinyl    acetate or vinylidene chloride/vinyl acetate copolymers.-   8) Polymer derivatives of α,β-unsaturated acids and derivatives    thereof, such as polyacrylates and polymethacrylates,    polyacrylamides and polyacrylonitriles.-   9) Copolymers of the monomers mentioned under 8) with one another or    with other unsaturated monomers, for example acrylonitrile/butadiene    copolymers, acrylonitrile/alkyl acrylate copolymers,    acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide    copolymers or acrylonitrile/alkyl methacrylate/butadiene    terpolymers.-   10) Polymers derived from unsaturated alcohols and amines or their    acyl and acetal derivatives, for example polyvinyl acetate,    polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl    butyrate, polyallyl phthalate or polyallylmelamine; and copolymers    thereof with the olefins mentioned under 1).-   11) Homopolymers and copolymers of cyclic ethers, for example    polyalkylene glycols, polypropylene oxides or copolymers thereof    with bisglycidyl ethers.-   12) Polyacetals such as polyoxymethylene and polyoxymethylenes which    contain ethylene oxides as comonomer; polyacetals modified with    thermoplastic polyurethanes, acrylates or MBS.-   13) Polyphenylene oxides and sulfides.-   14) Polyurethanes derived from polyethers, polyesters and    polybutadienes which have terminal hydroxyl groups on the one hand    and aliphatic or aromatic polyisocyanates on the other hand.-   15) Polyamides and copolyamides derived from diamines, dicarboxylic    acids and from aminocarboxylic acids of the corresponding lactams,    for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12    and 4/6, polyamide 11, polyamide 12, aromatic polyamides that are    obtained, by means of condensation, from m-xylene, diamine and    adipic acid; polyamides that are obtained from hexamethylenediamine    and isophthalic and/or terephthalic acid, with or without an    elastomer as modifier, for example poly-2,4,4-trimethylhexamethylene    terephthalamide or poly-m-phenylene isophthalamide; block copolymers    of the above-mentioned polyamides with polyolefins, olefin    copolymers, ionomers or chemically bonded or grafted elastomers; or    with polyethers, for example with polyethylene glycol, polypropylene    glycol or polytetramethylene glycol; and also polyamides or    copolyamides modified with EPDM or ABS, and polyamides condensed    during reaction (RIM polyamide systems).-   16) Polyureas, polyimides and polyamide imides and    polybenzimidazoles.-   17) Polyesters derived from dicarboxylic acids and diols and/or from    hydroxycarboxylic acids and lactones thereof, for example    polyethylene terephthalate, polybutylene terephthalate,    poly-1,4-dimethylolcyclohexane terephthalate, polyhydroxybenzoates,    and also block copolyether esters derived from polyethers having    terminal hydroxyl groups; and also poly-esters modified with    polycarbonates or MBS.-   17a) Polyesters derived from aliphatic dicarboxylic acids and diols    and/or oligo ethers and having the general formula    —(O—X—O—C(═O)—Y—C(O═))_(z)    wherein    -   X=—(CH₂)_(n)— wherein n=2 to 12 or    -   X=[—(CH₂)_(n)—O—(CH₂)_(n)—]_(r) wherein n=2 to 4 and r=2 to 10,    -   Y=—(CH₂)_(m)— wherein m=0 to 12,    -   and z=5 to 100    -   and copolymers thereof.-   18) Polycarbonates and polyester carbonates.-   19) Polysulfones, polyether sulfones and polyether ketones.-   20) Polyethers of diglycidyl compounds, including diglycidyl ethers    and diols, for example of diglycidyl ether of bisphenol A, and    bisphenol A.-   21) Natural polymers, such as rubber, and chemically modified    homologous derivatives of natural polymers, for example cellulose    acetates, cellulose propionates and cellulose butyrates, or    cellulose ethers, for example methyl cellulose (degree of    substitution >2.5); and also resins and derivatives thereof.-   22) Mixtures of the afore-mentioned polymers, for example PP/EPDM,    polyamide 6/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,    PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic    PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPE/HIPS,    PPE/PA6.6 and copolymers, PA/HDPE, PA/PP or PA/PPO.-   23) Mineral oils, fatty acid alkyl esters or rapeseed oil C₁-C₆alkyl    esters, in which case preference is given to rapeseed oil methyl    ester and rapeseed oil ethyl ester.

Examples of polymers that are commercially available and especiallysuitable for the composition according to the invention includeCOETHYLENE® SB 0425 and COETHYLENE® SL (polystyrenes, Plast Labor);HOSTAFLEX® CM 13 (polyvinyl chloride/vinyl acetate copolymer); ESTERGUM®8 D and 10 D (colophony glycerol ester); HOSTALITH® 3067 (polyvinylchloride); HOSTYREN® 2000, 5000 and 7000 (polystyrenes); solid acrylicresins such as PLEXIGUM® N 80 (polyethyl acrylate) and M 825 (polymethylmethacrylate); polyvinyl acetate copolymers such as MOWILITH® 20 and 50having molecular weights of 35 000 and 260 000 daltons, respectively;colophony derivatives NEOLYN® 20 and 35 D; polytetrahydrofurans;polypropylene glycols such as polyglycol T01/60 (Hoechst AG), polyvinylacetate, Edenor ME SU (rapeseed oil methyl ester, Henkel KGAA) and alsoMowilith 20 (polyvinyl acetate, Harco).

The molecular weight of the polymer of the oil phase stabilisers thatare suitable for the composition according to the invention, determined,for example, by light-scattering measurements or by measurement of theosmotic pressure, can be up to 1 000 000 and is usually from 1000 to 1000 000 daltons, preferably from 1000 to 100 000 daltons. In the case ofcompounds that are extremely hydrophobic and therefore of extremely lowsolubility in water, for example alkanes and fatty acid alkyl esters,the MW can also be less than 1000.

The oil phase stabilisers are used in the composition according to theinvention in a concentration of from 0.5 to 10% by weight, preferablyfrom 1 to 5% by weight, based on the complete formulation. In the caseof compounds that are extremely hydrophobic and therefore of extremelylow solubility in water, for example alkanes and fatty acid alkylesters, and that have a low molecular weight, the concentration of theoil phase stabilisers can be up to 25%.

Surface-active substances and dispersing agents that are suitable forthe present composition according to the invention includetristyrylphenol ethoxylates, for example Soprophor TS-10 (Rhone PoulencS. A.) or BSU (Rhodia Geronazzo Spa), EO/PO/EO block copolymers, forexample Pluronic F-108, Pluronic F-38, Pluronic P-105 (BASF WyandotteCorp.) and/or sodium salts of sulfonated naphthalenesulfonicacid-formaldehyde condensation products, for example Morwet D-425 (WitcoChem. Corp.) or Orotan SN (Rohm & Haas, France S. A.), lignosulfonates,PO/EO butanol copolymers, for example Atlox G-5000, block copolymers ofpolyhydroxystearic acid and polyalkylene glycols, for example Atlox 4912or 4914 (American Hoechst), or partially hydrolysed or fully hydrolysedpolyvinyl acetate, for example Mowiol 18-88 or Mowiol 4-88 (Hoechst AG).

The dispersing agents are preferably used in an amount of from 0.5 to 5%by weight, especially from 1 to 2% by weight, based on the completeformulation.

The formulations in accordance with the invention may additionallycomprise thickeners for the continuous aqueous phase. Any thickenergenerally customary in formulation technology and capable of increasingthe viscosity of the aqueous emulsions according to the invention issuitable, for example xanthan gum, clays or polyethylene glycols. Thethickeners are preferably used in a concentration of from 0.03 to 1%,based on the complete formulation of the aqueous emulsion.

In addition, there may also be added to the formulations according tothe invention substances that lower the melting point of the emulsions,that is to say that prevent the formulation from freezing at lowtemperatures (anti-freezing agents). Such substances are usuallywater-soluble salts that are suitable for lowering the freezing point ofthe aqueous phase of the emulsion according to the invention, forexample sodium chloride, potassium chloride, ammonium chloride, ammoniumnitrate and sodium nitrate and mixtures thereof. Also suitable arewater-soluble glycols, for example ethylene glycol, propylene glycol,diethylene glycol, glycerol and mixtures thereof. The salts and theglycols are, in each case, preferably used in a concentration of from0.5 to 10% by weight, based on the complete formulation of the emulsion.

The emulsions according to the invention may additionally comprise, asadjuvants, preservatives that inhibit the growth of micro-organisms suchas bacteria and fungi, for example Proxel GXL (benzisothiazolin-3-one,Avecia Inc.) or formaldehyde. Such adjuvants can be used in an amount offrom 0.1 to 0.5% by weight of the complete formulation.

Preparation of the emulsions according to the invention is substantiallycarried out using the methods described in U.S. Pat. No. 5,674,514. Theorganic phase can be prepared, for example, by dissolvingclodinafop-propargyl, optionally together with cloquintocet-mexyl, in ahydrophobic solvent, subsequently adding the water-insoluble oil phasestabiliser and then, where appropriate, heating.

The aqueous phase is prepared by dissolving a surface-active substanceand/or a dispersing agent in water, where appropriate adding substancesthat lower the freezing point.

The organic phase is then emulsified in the aqueous phase by means of asuitable stirrer, for example a YSTRAL® X 40/32 emulsifier, havingstirring speeds of from 3000 to 6000 rpm. Depending on the formulationused and the speed, an emulsion is obtained having particle sizes in thepreferred range of 1-10 micrometres. Thickeners and/or preservativesmay, where appropriate, be added to the formulation before or after theemulsification step.

Whereas commercial products will preferably be formulated asconcentrates, the end user will normally employ formulations dilutedwith water.

Preferred herbicidal compositions according to the invention have thefollowing general compositions (all figures in % by weight, based on thecomplete formulation):

Oil Phase:

5-25% clodinafop-propargyl 1-6% cloquintocet-mexyl 10-60% solvent 1-5%oil phase stabiliser

Aqueous Phase:

0.05-1% thickener 3-8% anti-freeze 1-5% surfactants 0.1-0.5% biocidereminder water (buffered)

PREPARATION EXAMPLES Example P1

Preparation of a Herbicidal Composition Containing 100 g ofClodinafop-propargyl

a) Preparation of the Thickeners

4 g of Proxel GXL are dissolved in 1946 g of water. Then, withmechanical stirring, 50 g of Biopolymer AG are added and stirring iscarried out for 15 minutes until homogeneity is achieved.

b) Preparation of the Buffer Solution

11.5 g of Na₃PO₄•12H₂O and 9.0 g of H₃PO₄ (75%) are dissolved in 1000 mlof water and the pH is adjusted to 4 (using Na₃PO₄•12H₂O or H₃PO₄).

c) Preparation of the Oil Phase

In a 500 ml glass beaker, at a temperature of 20° C., 100 g ofclodinafop-propargyl and 25 g of cloquintocet-mexyl are dissolved, withstirring, in 250 ml of Solvesso 200. 20 g of polystyrene are then added,and heating to a temperature of 65-70° C. is carried out. Afterdissolution of the ingredients is complete, the mixture is left to coolto a temperature of 20° C.

d) Preparation of the Aqueous Phase

In a 1500 ml glass beaker, at a temperature of 20° C., 10 g of PluronicF 108, 10 g of Morwet D-425, 50 g of propylene glycol, 30 g ofBiopolymer prepared as described under a) and 2 g of Proxel GXL aredissolved in 470 g of buffer solution prepared as described under b).

e) Preparation of the Aqueous Emulsion Concentrate

Using the YSTRAL X 40/32 emulsifier, the aqueous phase is stirred atabout 600 rpm and the oil phase is then added; the mixture is emulsifiedat about 5000 rpm over the course of from 3 to 4 minutes until aparticle size of from 2 to 4 micrometres is obtained. Then, in order toachieve the desired viscosity, 40 g of Biopolymer prepared as describedunder a) are added with stirring using a magnetic stirrer (in order toobtain the gel structure of the concentrate).

On the basis of that Example, the following compositions according tothe invention can also be prepared (percentages are % by weight, basedon the complete formulation):

Example C1

Clodinafop-propargyl Content of 50 g/l

Oil Phase

5% clodinafop-propargyl 1.25% cloquintocet-mexyl 38% rapeseed oil methylester 3.7% polystyreneAqueous Phase

0.07% xanthan gum 1% Pluronic F-108 0.2% Proxel GXL ˜51% water pH 4(buffer [0.1 M]: 1.15% Na₃PO₄ · 12 H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Example C2

Clodinafop-propargyl Content of 100 g/l

Oil Phase

10% clodinafop-propargyl 2.5% cloquintocet-mexyl 18% benzoic acid methylester 1.6% polystyreneAqueous Phase

0.2% xanthan gum 4.8% propylene glycol 2.0% Pluronic F-108/Morwet D-425(1:1) 0.2% Proxel GXL ˜60.7% water pH 4 (buffer [0.1 M]: 1.15% Na₃PO₄ ·12 H₂O, 0.91% H₃PO₄ (75%) 97.94% water)

Example C3

Clodinafop-propargyl Content of 100 g/l

Oil Phase

10% clodinafop-propargyl 2.5% cloquintocet-mexyl 35% isobornyl acetate2.5% polyvinyl acetateAqueous Phase

0.1% xanthan gum 4.9% propylene glycol 2.0% Pluronic F-108/Morwet D-425(1:1) 0.2% Proxel GXL ˜43% water pH 4 (buffer [0.1 M]: 1.15% Na₃PO₄ · 12H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Example C4

Clodinafop-propargyl Content of 100 g/l

Oil Phase

10% clodinafop-propargyl 2.5% cloquintocet-mexyl 34% isobornyl acetate2.4% polypropylene glycolAqueous Phase

0.1% xanthan gum 4.8% propylene glycol 2.0% Pluronic F-108/Morwet D-425(1:1) 0.2% Proxel GXL ˜44%  water pH 4 (buffer [0.1 M]: 1.15% Na₃PO₄.12H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Example C5

Clodinafop-propargyl Content of 150 g/l

Oil Phase

 15% clodinafop-propargyl 3.75%  cloquintocet-mexyl  45% Exxate 700 3.3%polyvinyl acetateAqueous Phase

0.08%  xanthan gum 5.0% propylene glycol 2.0% Pluronic F-108/MorwetD-425 (1:1) 0.2% Proxel GXL ˜26%  water pH 4 (buffer [0.1 M]: 1.15%Na₃PO₄.12 H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Example C6

Clodinafop-propargyl Content of 200 g/l

Oil Phase

20% clodinafop-propargyl  5% cloquintocet-mexyl 40% Solvesso 200(high-aromatic-content hydrocarbon mixture) 3.4%  polystyreneAqueous Phase

3.7% propylene glycol 2.0% Pluronic F-108/Morwet D-425 (1:1) 0.2% ProxelGXL ˜26%  water pH 4 (buffer [0.1 M]: 1.15% Na₃PO₄.12 H₂O, 0.91% H₃PO₄(75%), 97.94% water)

Example C7

Clodinafop-propargyl Content of 240 g/l

Oil Phase

 24% clodinafop-propargyl   6% cloquintocet-mexyl 24.6%  benzyl acetate3.2% polypropylene glycolAqueous Phase

0.05%  xanthan gum 4.8% propylene glycol 2.0% Pluronic F-108/MorwetD-425 (1:1) 0.2% Proxel GXL ˜35%  water pH 4 (buffer [0.1 M]: 1.15%Na₃PO₄.12 H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Example C8

Clodinafop-propargyl Content of 240 g/l

Oil Phase

24% clodinafop-propargyl  6% cloquintocet-mexyl 29% acetophenone/amylacetate (2:8) 2.5%  polystyreneAqueous Phase

0.03%  xanthan gum 5.0% propylene glycol 2.0% Pluronic F-108/MorwetD-425 (1:1) 0.2% Proxel GXL ˜31%  water pH 4 (buffer [0.1 M]: 1.15%Na₃PO₄.12 H₂O, 0.91% H₃PO₄ (75%), 97.94% water)

Before application, the concentrated formulations set out above arediluted with an amount of 400 litres of water per hectare.

Biological Examples

Clodinafop-propargyl is generally used on the plant or the locus thereofin rates of application of from 5 to 200 g/ha, especially from 10 to 50g/ha, more especially from 20 to 30 g/ha.

The rates of application of cloquintocet-mexyl are generally from 2 to100 g/ha, preferably from 2 to 50 g/ha, especially from 5 to 7.5 g/ha.

The concentration required to achieve the desired action can bedetermined by experimentation. It will depend on the type of action, thedevelopment stage of the cultivated plant and of the weed, as well as onthe application (place, time, method), and in dependence on thoseparameters can vary over a wide range.

The amount of safener to be applied in relation to the herbicide islargely dependent upon the type of application. In the case of fieldtreatment, which is effected either using a tank mixture with acombination of the safener and the herbicide or by the separateapplication of the safener and the herbicide, the ratio of herbicide tosafener is generally from 1:1 to 10:1, preferably 4:1.

The herbicidal activity of the aqueous emulsions according to theinvention is demonstrated in the following biological Examples:

Example B1

Herbicidal Action after Emergence of the Plants (Post-emergence Action)

Monocotyledonous and dicotyledonous weeds are grown under greenhouseconditions in standard soil in plastic pots. Application of the testsubstances is carried out when the plants are at the 3- to 6-leaf stage.Application is carried out in the form of an aqueous emulsion of thetest substances in 400 litres of water per hectare. The rates ofapplication depend on the optimum doses ascertained under fieldconditions and greenhouse conditions. The tests are evaluated after 20days (% action, 100%=plant has died, 0%=no phytotoxic action).

Test plants: Alopecurus, Lolium rigidum, Lolium multiflorum, Agrostis.

Compositions of the Formulations Used

Composition no. C9 according to the present invention

Ingredient: Amount in % by weight clodinafop-propargyl (herbicide) 10.0cloquintocet-mexyl (safener) 2.5 benzoic acid methyl ester (solvent)18.0 polypropylene glycol T01/60 (oil phase 1.6 stabiliser) PluronicF-108 (surfactant) 1.0 Morwet D-425 (surfactant) 1.0 propylene glycol(anti-freeze agent) 4.8 xanthan gum (thickener) 0.2 Proxel GXL (biocide)0.2 water buffer pH 4 60.7 (buffer [0.1 M]: 1.15% Na₃PO₄.12 H₂O 0.91%H₃PO₄ (75%), 97.94% water)

Composition no. C10 according to the present invention

Amount Ingredient: in % by weight clodinafop-propargyl (herbicide) 10.0cloquintocet-mexyl (safener) 2.5 Exxate 700 (solvent) 24.0 polystyrene(oil phase stabiliser) 1.9 Pluronic F-108 (surfactant) 1.0 Morwet D-425(surfactant) 1.0 propylene glycol (anti-freeze agent) 4.7 xanthan gum(thickener) 0.2 Proxel GXL (biocide) 0.2 water buffer pH 4 54.5 (buffer[0.1M]: 1.15% Na₃PO₄.12 H₂O 0.91% H₃PO₄ (75%), 97.94% water)

Composition no. C11 according to the present invention

amount Ingredient: in % by weight clodinafop-propargyl (herbicide) 10.0cloquintocet-mexyl (safener) 2.5 Solvesso 200 (solvent) 25.0 polyglycol(o.p.s.) 2.0 Pluronic F-108 (surfactant) 1.0 Morwet D-425 (surfactant)1.0 propylene glycol (anti-freeze agent) 4.9 xanthan gum (thickener) 0.2Proxel GXL (biocide) 0.2 water buffer pH 4 53.2 (buffer [0.1M]: 1.15%Na₃PO₄.12 H₂O 0.91% H₃PO₄ (75%), 97.94% water)

Emulsifiable concentrate EC 100 of clodinafop-propargyl andcloquintocet-mexyl known under the trade name CELIO®

Ingredient: [% by weight] clodinafop-propargyl (herbicide) 10.0cloquintocet-mexyl (safener) 2.5 castor oil polyglycol 36-37(surfactant) 8.32 dodecyl-benzenesulfonic acid calcium 6.66 salt, linear(surfactant) 1-methyl-2-pyrrolidone (solvent) 20.0 soybean oil,epoxidised (dispersing 1.0 agent) high-aromatic-content hydrocarbonremainder mixture (solvent) (Solvesso 200)

Before application, the concentrated formulations set out above arediluted with an amount of 400 litres of water per hectare.

TABLE B1 Post-emergence action; rate of application ofclodinafop-propargyl: 30 g/ha: rate of application ofcloquintocet-mexyl: 7.5 g/ha: Formulation no.: Test plant: C9 C10 C11 EC100 Alopecurus 95 90 90 80 Lolium rigidum 90 90 90 80 Lolium multiflorum95 95 90 80 Agrostis 60 50 40 30

Table B1 shows that, in this test, the compositions according to theinvention have surprisingly improved herbicidal action on the testedweeds compared to the known emulsifiable concentrate (EC 100).Especially in the case of Alopecurus and Lolium, it was possible for theherbicidal action to be increased almost to complete destruction of theweed (95% herbicidal action).

In addition to the surprisingly improved herbicidal activity ofclodinafop-propargyl, the compositions according to the invention havethe following advantageous properties:

-   -   stable emulsion droplets are formed which, even when stored for        a relatively long period, exhibit no appreciable particle size        growth and no phase separation;    -   the clodinafop-propargyl and the cloquintocet-mexyl, which is        optionally present in addition, have a high degree of chemical        stability, resulting from appropriate selection of the solvent        and pH buffer system;    -   a high degree of stability in the cold, and therefore good        suitability for storage even at low temperatures;    -   no crystallisation of the herbicide or safener occurs in the        event of temperature changes; and    -   no phase separation occurs in the event of freeze/thaw cycles.

1. A herbicidal composition in the form of an aqueous emulsion whichcomprises a), as organic phase, a solution of a herbicidally effectiveamount of the compound2-(4-(5-chloro-3-fluoro-2-pyridyloxy)-phenoxy-propionic acid propargylester in a hydrophobic solvent and a substantially water-insoluble andhydrolysis-stable oil phase stabiliser and b), as aqueous phase, asolution of a pH buffer and at least one surface-active compound and/ordispersing agent in water.
 2. A composition according to claim 1, whichcomprises an amount, effective for antagonism of the herbicide, of2-(5-chloroquinolin-8-yloxy)-1-methylhexyl ester, its free acid or asalt thereof of formula

wherein M is a mono-, bi- or tri-valent metal, ammonium, N(R)₄ orHN(R)₃, wherein the substituents R are identical to or different fromone another and are C₁-C₁₆alkyl or C₁-C₁₆-hydroxyalkyl, or M is S(R₁)₃or P(R₁)₄, wherein the substituents R₁ are identical to or differentfrom one another and are C₁-C₂₀alkyl, C₂-C₂₀alkenyl, C₂-C₂₀alkynyl, arylsubstituted by C₁-C₂₀alkyl, C₂-C₂₀alkenyl or by C₂-C₂₀ alkynyl orheteroaryl substituted by C₁-C₂₀alkyl, C₂-C₂₀alkenyl or byC₂-C₂₀alkynyl, or 2 substituents R₁ together with the sulfur orphosphorus atom to which they are bonded form a 5- or 6-membered ring.3. A composition according to claim 1, which comprises an amount,effective for antagonism of the herbicide, of2-(5-chloroquinolin-8-yloxy)-1-methylhexyl ester.
 4. A method ofcontrolling undesired plant growth, which comprises applying aherbicidally effective amount of a composition according to claim 1 tothe plants or to the locus thereof.